1. Field of the Invention
The present invention is directed to apparatus for extracting an element from an assembly useful in the manufacture and repair of tubular products and, more specifically, to apparatus for extracting an element from a tubular member as required during disassembly of an automotive drive shaft.
Automotive drive shafts sometimes referred to as drive lines are comprised of a tubular member having an element such as a yoke of a universal joint, a bearing stub or one component of a slip joint fitted at each end thereof. Such elements are usually pressed into the hollow interior of the tubular member and secured by a circumferential weld joint effected between the end of the tubular member and a surface of the inserted element.
In automotive applications, drive shafts are utilized, either singularly or in combination, as a torque transmitting component(s) of the power train and are most commonly located under the vehicle between the transmission or other gear box and the differential of a drive axle. The ends of the drive shaft are usually connected to other components of the power train by a yoke which is fitted to one end of the drive shaft and connected by means of a universal joint cross shaped journal to another yoke receiving or delivering torque from or to an adjacent component of the power train.
Torque transmitting drive shafts of this type, especially when employed on commercial vehicles and heavy duty trucks, are subject to sudden changes in torque and exposed to road hazards which, during the life of the vehicle, may cause wear or damage to the drive shaft. In the event of such wear or damage, the drive shaft may be removed and replaced in its entirely which is rather expensive. Depending upon the nature of the wear and/or damage incurred, the drive shafts may also be disassembled and repaired which is less expensive than replacing the unit, however, this option depends upon the availability of equipment necessary to disassemble and reassemble the drive shaft assembly.
2. Description of the Prior Art.
Various types of machinery and equipment such as lathes, vises, presses, cutting tools and welding devices have been employed to repair drive shafts in the past. These are general purpose devices and have usually been used to perform only a single function in the assembly and/or disassembly of driveshafts. Some of the equipment, for example, lathes and presses, are relatively expensive when used to perform only a single function. The assembly and disassembly of drive lines has also required high labor costs since the work pieces have traditionally been moved from one machine to another for each sequential operation and the drive shafts, some of which may be ten to twelve feet long, have to be set up for each separate operation.
One machine developed specifically for working an automotive drive shafts is disclosed in U.S. Pat. No. 3,758,098. That machine is similar to a lathe having a head stock and movable tail stock mounted to a relatively long support bed. The drive shaft is mounted between the tail stock and the head stock which includes a hydraulic jack. The machine disclosed by U.S. Pat. No. 3,758,098 requires an adaptor in the form of a U-joint yoke, a U-joint cross and a yoke on the drive shaft to mount the drive shaft or work piece in the machine. The machine is also relatively long and cumbersome considering that work is usually performed at only one end of the drive shaft at any one time.
The present invention avoids many of the problems encountered when attempting to disassemble and repair tubular articles such as automotive drive shafts by providing apparatus in the form of a chuck having a plurality of jaws some of which abut and prevent movement of the end of the tubular element while other jaws engage and pull the element from the interior of the tubular member.